Saturday, May 16, 2009

Free Throw Accuracy - NBA Moneyball with Dr. Tom

Dr. Tom Amberry, at the age of 71, made 2,750 free throws in a row. He didn't miss, he was asked to leave, as they were closing the gym.

NBA players make 77% of their foul shots, a relatively disgraceful figure. (BTW, the NBA free throw percentage is basically identical to the WNBA.)

Dr. Tom's training regime seems to get results for others. He claims to have improved a junior high team from 40% to 80%+ in a week. If he could take an NBA team from 77% to 85%, he would be worth an astonishing 10 wins a season.

Here's the math:
- The average NBA team shoots 25 FTs per game
- Increasing FT % by 8 percentage points results in 2 extra points per game
- 12.5% of games are won by 2 points or less (includes OTs)
- 12.5% of 82 games is 10.3 extra wins

An extra 10 wins would have put any of these seven teams into the playoffs this year: Phoenix, Indiana, Charlotte, New Jersey, Milwaukee, Toronto, and New York. But no, they missed free throws and the playoffs.

This year, if Orlando had made one extra free throw (here's looking at you Dwight and Hedo) in regulation in Games 2 and 4, the Magic would have led the series by 3-2. Orlando did overcome the worst FT% in the regular season this year (71.5%), but it caught up with them in the end. Without any doubt, poor FT shooting prematurely ended the Magic's championship bid.

There are probably less than a dozen players in the NBA who are worth an extra 10 wins per season. All of them make more than $10 million per year than the average player. I don't know how much Dr. Tom charges, but I assume it is less.

This NYT article says that NBA free throw shooting hasn't improved in 50 years. This freakonomics post says that while the average player hasn't improved, the top players have improved a lot (which means the worst have gotten worse, yikes!).

Maybe some variable pay in the NBA would cause improvement. Or hiring Dr. Tom. Or both.

* Thanks to Tim Katlic for researcing this post.


  1. While obviously these stats make sense and are precisely measurable, they are also only a partial picture.

    If an NBA team could win with all 90% free throw shooters, it would have tried it by now. To give a counter example, rebounding is also an impact statistic, since more opportunities to score lead to more made baskets. As a (now former) Sonics fan, I clearly remember Dennis Rodman winning two games for Chicago in the '96 finals due to his amazing ability to rebound. Dennis Rodman's career FT% is 58%.

    The correct overall context for winning is always team. All relevant statistics are important, but without given a proper context one can easily make the mistake of using the importance of one facet of the game to throw the overall system fatally out of balance.

  2. Regarding the dollar value of 10 wins, you shouldn't look at the salary of a player who's worth 10 wins. The worth of a player, weather measured in wins or in dollars, isn't measured against the absence of the player on the court, but rather against the next best player available. You've incorporated this precept intuitively when you talk about a player who's worth 10 wins (after all, a team that played down a man would be lucky to win any games at all), but not when you talk about their salaries being $10M/yr. The real dollar worth to a team of its star player is the difference between his salary and the salary of the guy who would come off the bench if the star got injured.

    Re the previous comment about the value of good FT shooters on the team: the point is that if Dennis Rodman could spend an extra half-hour per day working with Dr. Tom, and thereby improve his FT% from 58 to 68, it seems likely that that'd improve his overall contribution to the team. You're right in that it's probably not worth it for Rodman to get his FT% up to 90--there are deminishing returns here, both in time spent per % improvement in shooting, and also because the better he gets at shooting FTs, the less likely opponents are to foul him, making his skill at FTs less important--but if his FT% is worse than a team of high school students coached by Dr. Tom, then it might be worthwhile to have the good doctor on retainer.